Laboratory-designed biocomposites structured by organic matrices impregnated with oriented biominerals have been significantly progressed by mimicking biological processes, although several problems associated with their formulation or antigenicity remain to be solved. Here, we describe a new strategy for the formulation of bioinspired nanostructures that involves spontaneous mediation by cooperative interactions between inorganic nanocrystals and host cells without the complex procedures required for laboratory-designed biocomposites. In the present study, osteoblastic cells were cultured on hydroxyapatite and beta-tricalcium phosphate nanocrystals prepared by discharging in electrolytes. Specifically, a high level of assembly of collagenous proteins associated with cell proliferation was achieved on nanoscale beta-tricalcium phosphate crystals by catalysis of polyphosphate chains produced during cell culture. Furthermore, a spatial structure that was practically composed of natural biocomposites found in bone and teeth was obtained on the nanocrystals due to increased cross-linking between inorganic molecules and biomolecules. Suggestions for the spontaneous formulation of bioinspired nanostructures in a living body mediated by inorganic biomaterials are also discussed.
(c) 2007 Wiley Periodicals, Inc.